# Rulers of the Open Sky at Risk: Climate-Driven Habitat Shifts of Three Conservation-Priority Raptors in the Eastern Himalayas

## TL;DR

This study shows that climate change is causing severe habitat loss for three raptor species in the Eastern Himalayas, with some losing over 90% of their suitable habitats by 2080.

## Contribution

The study provides the first detailed climate change impact assessment for raptors in the Eastern Himalayas using ensemble species distribution modeling.

## Key findings

- Falco severus is projected to lose 33–41% of its suitable habitat by 2080.
- Gyps tenuirostris may lose 53–96% of its suitable habitat due to climate change.
- Haliaeetus leucoryphus is expected to lose 94–99% of its suitable habitat by 2080.

## Abstract

Raptors, as apex predators, serve as valuable bioindicators for assessing the impacts of climate change because of their specialized ecological traits, which render them particularly susceptible to environmental alterations. Globally, raptors are experiencing significant conservation concerns, with approximately 52% of species exhibiting declining populations and 18% being classified as threatened. Despite this, the effect of climate change on raptors is poorly studied in the Eastern Himalayan region. Three species, Falco severus, Gyps tenuirostris and Haliaeetus leucoryphus, were selected based on their conservation status in the region. This study provides a comprehensive assessment of climate change impacts on raptors in the northeastern part of the Eastern Himalayas, utilizing ensemble species distribution modeling for the projected periods 2041–2060 and 2061–2080. The future projections indicate a substantial decline in suitable habitats: Falco severus is projected to lose 33–41%, Gyps tenuirostris may lose 53–96%, and Haliaeetus leucoryphus is anticipated to experience a loss of approximately 94–99% of its suitable habitats.

Raptors, being at top of the food chain, serve as important models to study the impact of changing climate, as they are more vulnerable due to their unique ecology. They are vulnerable to extinction, with 52% species declining population and 18% are threatened globally. The effect of climate change on raptors is poorly studied in the Eastern Himalayan region. The present study offers a complete investigation of climate change effects on the raptors in the northeast region of the Eastern Himalayas, employing ensemble species distribution modeling. The future predictions were employed to model the climate change across two socioeconomic pathways (SSP) i.e. SSP245 and SSP585 for the periods 2041–2060 and 2061–2080. Specifically, five algorithms were employed for the ensemble model, viz. boosted regression tree (BRT), generalized linear model (GLM), multivariate adaptive regression splines (MARS), maximum entropy (MaxEnt) and random forest (RF). The study highlights worrying results, as only 10.5% area of the NE region is presently suitable for Falco severus, 11.4% for the critically endangered Gyps tenuirostris, and a mere 6.9% area is presently suitable for the endangered Haliaeetus leucoryphus. The most influential covariates were precipitation of the driest quarter, precipitation of the wettest month, and temperature seasonality. Future projection revealed reduction of 33–41% in suitable habitats for F. severus, G. tenuirostris is expected to lose 53–96% of its suitable habitats, and H. leucoryphus has lost nearly 94–99% of its suitable habitats. Such decline indicates apparent habitat fragmentation, with shrinking habitat patches.